A lioness has killed the father of her three cubs in their pen at a zoo in the US, officials say.

Zuri, 12, attacked 10-year-old Nyack and staff at Indianapolis Zoo could not separate the pair. He died of suffocation.

The lions had lived in the same enclosure for eight years, and had three cubs together in 2015.

In a Facebook post the zoo said staff would conduct a “thorough review” to try to find out what happened.

“Nyack was a magnificent lion and he will be greatly missed,” it read.